The invention relates to the field of micro-electromechanical systems (MEMS) for electrical switching, and in particular to a polymeric liquid metal switch.
Liquid metal switches have been devised that use the heating of gases to create pressure changes that actuate the switches by creating gaps in liquid metal drops trapped in channels (to open electrical contacts) and moving the drops to wet between contacts (to close electrical contacts). The current method used to manufacture the channel structures has resolution and accuracy limits because it uses sandblasting to form the channels. In addition, the way the heater resistors are currently formed on the ceramic substrate causes energy inefficiencies from heat loss into the ceramic substrate.
The present invention relates to a polymeric switch in which a switching channel is formed in a polymer layer. The channel may be formed by micro-machining techniques such as laser ablation or photo-imaging. A liquid metal switch is contained within the switching channel. The liquid metal switch operates by making or breaking an electrical contact using a volume of liquid metal. Contact pads within the switching channel are wettable by the liquid metal and provide a latching mechanism for the switch. The switch is amenable to manufacture by micro-machining for small size.